A notluck is a gathering where food will be eaten, but unlike a potluck, the food you bring is just for yourself (meaning you can opt not to bring food if you're not hungry).

"We had a potluck for the last movie night and Shannon was the only one who brought food. So this time, it's a notluck: you're all on your own for dinner. And it's still BYOB, you drunks; the company is not springing for your beer."